The driver and firmware sync up through SYNC messages, and the
firmware's affirmative reply to these SYNC messages appears to be the
"Reset" indication received via the status interrupt endpoint.  Thus the
driver needs the status interrupt endpoint always active so that the
Reset indication can be received even if the netdev is closed, which is
the case right after device insertion.

Signed-off-by: Dan Williams <redacted>
---

diff --git a/drivers/net/usb/sierra_net.c b/drivers/net/usb/sierra_net.c
index 18dd425..e6e2857 100644
--- a/drivers/net/usb/sierra_net.c
+++ b/drivers/net/usb/sierra_net.c

@@ -905,7 +905,7 @@ static struct sk_buff *sierra_net_tx_fixup(struct usbnet *dev,
 
 static const struct driver_info sierra_net_info_direct_ip = {
 	.description = "Sierra Wireless USB-to-WWAN Modem",
-	.flags = FLAG_WWAN | FLAG_SEND_ZLP,
+	.flags = FLAG_WWAN | FLAG_SEND_ZLP | FLAG_INTR_ALWAYS,
 	.bind = sierra_net_bind,
 	.unbind = sierra_net_unbind,
 	.status = sierra_net_status,